Band vs Prism vs Contour Volumes

The terrace volume calculation functions (Terrace Volume, Fixed Slope Banks and Variable Slope Banks) allow you to output details of the volumes in depth ranges.

All three calculation methods result in the same overall cut and fill volumes. In other words, your choice of calculation method does not affect the volume calculation in any way, it merely changes the way the volume calculation is reported.

There are three ways of calculating the volumes by depth range:

Band

The Band method of calculation subdivides the calculated volume for a particular depth into the various depth bands consisting of the actual cut or fill depth AND all the preceding bands. This is in accordance with the SABS 1200 method of volume calculation.

For the following depth increments:

The volumes are calculated as follows.

The following output results.

  Terrace Volume

  ==============

 

  Volume for Terrace :

  Ground Surface     : Surface 1

  Terrace Surface    : Surface 2

  Grid Interval      : 0.100

 

  The unadjusted volumes are :-

      240.00 cu.m. total Cut.

      240.00 cu.m. total Fill.

      127.20 sq.m. total area in Cut.

      127.20 sq.m. total area in Fill.

  NOTE: Volume table is calculated in bands

 

     Depth (m)         Cut (cu.m.)      Fill (cu.m.)

  ================     ===========      ============

   0.000 to  0.625         75.781            75.781

   0.625 to  1.250         65.094            65.094

   1.250 to  1.875         54.688            54.688

   1.875 to  2.500         44.438            44.438

   2.500 to  3.125          0.000             0.000

   3.125 to  4.000          0.000             0.000

   4.000 to  5.000          0.000             0.000

 

Using the Band method of calculating volumes:

Prism

The Prism method of calculation assigns the entire calculated volume for a particular depth to the depth band of the actual cut or fill depth.

For the following depth increments:

The volumes a calculated as follows.

The following output results.

  Terrace Volume

  ==============

 

  Volume for Terrace :

  Ground Surface     : Surface 1

  Terrace Surface    : Surface 2

  Grid Interval      : 0.100

 

  The unadjusted volumes are :-

      240.00 cu.m. total Cut.

      240.00 cu.m. total Fill.

      127.20 sq.m. total area in Cut.

      127.20 sq.m. total area in Fill.

 

  NOTE: Volume table is calculated by prism

 

     Depth (m)         Cut (cu.m.)      Fill (cu.m.)

  ================     ===========      ============

   0.000 to  0.625          5.219             5.219

   0.625 to  1.250         15.906            15.906

   1.250 to  1.875         26.313            26.313

   1.875 to  2.500        192.563           192.563

   2.500 to  3.125          0.000             0.000

   3.125 to  4.000          0.000             0.000

   4.000 to  5.000          0.000             0.000

   5.000 to  6.000          0.000             0.000

   6.000 to  7.000          0.000             0.000

   7.000 to  8.000          0.000             0.000

       Over  8.000          0.000             0.000

                       -----------      ------------

                          240.000           240.000

                       -----------      ------------

Using the Prism method of calculating volumes, the volume of excavation from 0m-2.5m is calculated and assigned to the depth range 2m-3m.

There is a relationship between Band and Prism calculations, in that the volume for any depth range calculated by the Prism method is equal to the sum of the volume for that depth range AND all preceding depth ranges when calculated by the Band method.

Contours

The Contour calculation method assigns the entire calculated volume between two consecutive contours to the contour band of the actual cut or fill depth.

For the following contour interval:

The volumes are calculated as follows.

The following output results.

   Terrace Volume

  ==============

 

  Volume for Terrace :

  Ground Surface     : Surface 1

  Terrace Surface    : Surface 2

  Grid Interval      : 0.100

 

  The unadjusted volumes are :-

      240.00 cu.m. total Cut.

      240.00 cu.m. total Fill.

      127.20 sq.m. total area in Cut.

      127.20 sq.m. total area in Fill.

  NOTE: Volume table is calculated by contour

 

    Contour (m)        Cut (cu.m.)      Fill (cu.m.)

  ================     ===========      ============

  522.000 to 523.000         35.200             0.000

  523.000 to 524.000         89.600             0.000

  524.000 to 525.000        115.200             0.000

  525.000 to 526.000          0.000           115.200

  526.000 to 527.000          0.000            89.600

  527.000 to 528.000          0.000            35.200

                       -----------      ------------

                            240.000           240.000

                       -----------      ------------

  Volumes adjusted for 100.00% compaction and 0.00m topsoil stripping :-

      240.00 cu.m. Cut available for Fill

      240.00 cu.m. of Fill is required giving:-

        0.00 cu.m. of Fill shortfall and:-

        0.00 cu.m. of Topsoil to be stripped